Fuel delivery systems, especially those for delivering fuel for an internal combustion engine have not been altogether satisfactory. Particularly inefficient is the typical carburetor for delivering gasoline to an automobile or similar engine. The rate of supply of fuel to the carburetor is controlled by such elements as a float chamber, float and needle valve. The carburetor also includes such components as a throttle valve, regulating screws, inlet valves, springs, nozzle, linkages, and the like. However, as efficient as a well adjusted or tuned carburetion fuel delivery system is for a particular engine, it will not remain so long because of engine and carburetor component wear resulting in changing fuel requirements and deliveries which are not compensated for. Moreover, as such wear and changes continue there results in still further inefficiency of the system. Accordingly, in order to maintain peak, or in some cases even acceptable, engine running and fuel delivery conditions, frequent tune-ups and carburetor adjustments must be made. The carburetor, working on mechanical valves and linkages delivers fuel in response to the amount of accelerator depression and with the exception of an automatic choke, makes no compensation or adjustment for engine condition or wear or efficiency. Also carburetors as well as fuel injection systems often require significant maintenance, and performance is significantly affected by temperature, pressure, vibration and other environmental conditions. In short, presently devised fuel delivery systems simply fall short in achieving precisely measured fuel quantities needed by an engine at any given instant. Yet such fuel delivery is quite important not only for maximum engine performance, regardless of whether it is operating at idle, cruising or accelerating, but also for the sake of fuel economy. It is such problems that the present invention is intended to obviate.